Saturday, 18 April 2015

Discovered Tribe’s Bacteria May Point to Our Past

April 17, 2015 -- A tribe of Indians found in the remote mountains of Venezuela may have a lot to teach us about the connection between gut bacteria and our health.

The Yanomami Indians have nearly twice as many different kinds of bacteria living in their intestines as Americans do.

Researchers say the discovery offers a peek at an unspoiled microbiome, the collection of trillions of bacteria that live in and on our bodies. We’re still learning about the roles these friendly microbes play in our health. But studies have shown they influence our weight, our digestion, our immune responses, and they help keep disease-causing pathogens from making us sick.

As scientists have begun to appreciate the importance of the microbiome, there’s been growing concern that modern practices may be changing it in ways that lead to disease. These include everything from more and more processed foods in our diets, to the rise in C-sections (which deny infants the chance to be protected by Mom’s bacteria), to the overuse of antibiotics.

And though the villagers told medical workers they’d never before had contact with outsiders, scientists found the bacteria living in and on their bodies had genes to shield it from modern antibiotics. This suggests that the problem of antibiotic resistance may be tougher to undo than experts once thought.

“This population of Yanomami Indians that we studied are naive to [modern] practices. They present a unique opportunity to put our microbial past under the microscope, if you wish, and characterize for the first time a microbiome that perhaps could be similar to that of our ancestors,” says researcher Jose Clemente, PhD, an assistant professor of genetics and genomics at the Mount Sinai School of Medicine, in a news briefing.

Researchers say the tribe was spotted by helicopter in 2008. A medical team made contact with the group in 2009. They asked permission to collect samples of bacteria swabbed from their mouths, skin, and feces. They collected samples from 34 of the 54 villagers who ranged in age from 4 to 50.

There were some signs of modern life amongst tribe members’ belongings, including T-shirts, metal cans, and machetes. Researchers believe they got these items through trade with other Yanomami groups that had made contact with the outside world.

Samples of their bacteria were flown back to the U.S. and analyzed from 2011 to 2014.